Low Tech Integrity of Data Transmission Test

[houseisland]

A friend showed me this. I have had to use it a couple of times.

Situation: Weird intermittent network errors, file corruption, applications crashing on workstations. No network diagnostic tools.

Low Tech Test: Create a large (several Mb) text file in Wordpad -- all zeros. Suck it back and forth through network connections. Open file and seach for ones (1) after each transmission.

This cheap test has helped me narrow down problems to individual bad NICs when no other resources were available..

[NooNoo]

Good tip, thank you!

[Six Eyed Smily]

never thought of that! thanks

[Ya_know]

But will this really work? I don't mean to look down on any of this, but right now it is just a mater of opinion. Is there any validity to this, as in any links to reputable sites explaining that this is true?

[houseisland]

No links to web sites. However, I have seen it work. I have used it.

It is obviously not at test for all network problems, but where a NIC is causing data corruption a large enough all-zeros text file passing through it will end up with a small number of ones in it. If the problem with the NIC is highly intermittent the usefulness of this test is reduced, however.

In one situation, larger PDF files pulled from a file server to a terminal server could not be opened in a terminal session. Acrobat reader would crash. Executable files copied to the terminal server would not run or would crash. Strange things would happen with larger data files. Using the text file together with trial and error in a process of elimination narrowed the problem down to one of the NICs in the terminal server.

When you come across a bad NIC, try it out. There is nothing like seeing for yourself.

[Radical Dreamer]

One flaw that I see with this is, why does it have to be a 1? If the data is flawed upon receipt, 0000 0000 could show up as 1010 1010 or 0011 1100 or any other combination, so actually you should look for ANY abnomrality, not just 1's

[FatalException0E]

Originally posted by Radical Dreamer
One flaw that I see with this is, why does it have to be a 1? If the data is flawed upon receipt, 0000 0000 could show up as 1010 1010 or 0011 1100 or any other combination, so actually you should look for ANY abnomrality, not just 1's

So write us a search routine that'll search for everything EXCEPT 0......actually, where's my Vis Studio pack?.......

[Radical Dreamer]

Originally posted by FatalException0E
So write us a search routine that'll search for everything EXCEPT 0......actually, where's my Vis Studio pack?.......

That wouldnt be too hard, but I dont have a copy of VB now that I am no longer a student